Textured ligating band and method of use of same

ABSTRACT

An elastic band for ligating tissue within a living body comprises an inner tissue engaging surface which, when in an operative position within the body, surrounds and directly contacts the tissue. At least a portion of the inner tissue engaging surface defines a plurality of discontinuities formed by one of projections and depressions. A method of ligating tissue within a living body using such a ligating band comprises the steps of positioning the elastic band, which has been stretched to increase the size of a central opening extending therethrough, adjacent to a portion of tissue to be ligated. The tissue to be ligated is then drawn through the central opening of the elastic band and the elastic band is released so that the size of the central opening decreases to grip the tissue received therein.

This application is a continuation of application Ser. No. 08/866,989filed Jun. 2, 1997, now U.S. Pat. No. 5,976,158.

FIELD OF THE INVENTION

The invention relates generally to the field of tissue ligation, andmore particularly to an improved ligating band and a method of use ofthe ligating band to ligate tissue.

BACKGROUND OF THE INVENTION

Physicians have used elastic ligating bands to treat lesions, includinginternal hemorrhoids and mucositis and for performing mechanicalhemostasis.

The object of ligation is to position a ligating band over the targetedlesion or blood vessel section by stretching the band beyond itsundeformed diameter drawing the tissue to be ligated within the band andthen releasing the band so that it contracts, applying inward pressureon the section of tissue caught within the band. The effect of theinward pressure applied by the band is to stop all circulation throughthe targeted tissue, thereby causing the tissue to die. The body thensloughs off the dead tissue or the dead tissue may be aspirated into anendoscope or a similar device.

U.S. Pat. No. 5,356,416 to Chu et al. and U.S. Pat. No. 5,398,844 toZaslavsky et al., both of which are incorporated herein by reference,describe ligating band dispensing devices including cylindrical supportsurfaces over which elastic ligating bands are stretched. Thecylindrical support surfaces are typically attached to the distal end ofan endoscope which is advanced into the body to a target area. A userthen applies suction through the endoscope to draw the tissue to beligated into the cylindrical support surface and then releases aligating band to contract around the tissue.

There are two problems inherent with the type of ligating bandstypically used with the above-described devices. The first is that thebands have a tendency to slip off the targeted tissue before the tissueis completely ligated. One reason why a ligating band may slip offtargeted tissue is because tissue contained within a ligating band iseffectively “pinched” by the ligating band, creating an outward pressureon the band. Specifically, the bulb-shaped projection of tissue whichhas been drawn under suction into the lumen of a cylindrical supportsurface is pulled away from the surrounding tissue creating tensionwithin the projection which draws the tissue of the projection backtoward the its natural position. Thus, the tissue is urged to slip outof the ligating band as the band contracts. In addition, blood and fluidwithin the body can make the surface of the targeted tissue slick,thereby decreasing the coefficient of friction between the ligating bandand the targeted tissue. Also, if the targeted tissue is an active bloodvessel the “pulsing” effect of blood moving through the vessel can causethe ligating band to slip off of the targeted tissue.

A second problem with current ligating bands is that the bands are notadjustable once they have been dispensed from the ligating banddispenser. Therefore, if a band is improperly placed around a section oftissue, or if the physician placing the ligating band should wish todraw more tissue within the band, there is no effective way to adjustthe band.

SUMMARY OF THE INVENTION

The present invention is directed to an elastic band for ligating tissuewithin a living body comprising an inner tissue engaging surface which,when in an operative position within the body, surrounds and directlycontacts the tissue. At least a portion of the inner tissue engagingsurface defines a plurality of discontinuities formed by one ofprojections and depressions. A method of ligating tissue within a livingbody using such a ligating band comprises the steps of positioning theelastic band, which has been stretched to increase the size of a centralopening extending therethrough, adjacent to a portion of tissue to beligated. The tissue to be ligated is then drawn through the centralopening of the elastic band and the elastic band is released so that thesize of the central opening decreases to grip the tissue receivedtherein.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood through the followingdetailed description, with reference to the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a first ligating band according to aembodiment of the present invention;

FIG. 2 is a perspective view of a ligating band according to a secondembodiment of the present invention;

FIG. 3 is a perspective view of a ligating band according to a thirdembodiment of the present invention;

FIG. 4 is a perspective view of a ligating band according to the secondembodiment of the present invention, wherein the texturing isperpendicular to the band's centerline axis;

FIG. 5 is a perspective view of a ligating band according to the thirdembodiment of the present invention, wherein the texturing isperpendicular to the band's centerline axis;

FIG. 6 is a perspective view of a ligating band according to the secondembodiment of the present invention, wherein the texturing is angled tothe band's centerline axis;

FIG. 7 is a perspective view of a ligating band according to the thirdembodiment of the ligating band depicted in FIG. 3, wherein thetexturing is angled to the band's centerline axis;

FIG. 8 is a perspective view of an alternate embodiment of the ligatingband depicted in FIG. 2, wherein the texturing is parallel to the band'scenterline axis, and showing manipulation apertures;

FIG. 9 is a perspective view of an alternate embodiment of the ligatingband depicted in FIG. 3, wherein the texturing is comprised of securingprongs, and showing manipulating apertures;

FIG. 10 is a perspective view of an alternate embodiment of the ligatingband depicted in FIG. 9, wherein the securing prongs are configured asinjection prongs;

FIG. 11 shows a side view of a blood vessel drawn into a device forapplying ligating bands;

FIG. 12 shows a side view of a blood vessel with an elastic ligatingband received thereon;

FIG. 13 shows a side view of a blood vessel received within a device forapplying ligating bands wherein the elastic ligating band has beenreopened on the blood vessel to adjust its position;

FIG. 14 shows a side view of the blood vessel of FIG. 13, wherein theelastic ligating band has been released;

FIG. 15 shows a side view of a ligating band of FIG. 9, wherein aligating band spreading device is being used to stretch the ligatingband while a mechanical gripping device is used to draw tissue throughthe central opening in the ligating band;

FIG. 16 shows a side view of the ligating band of FIG. 9 wherein theligating band spreading device has been inserted through a centralchannel formed through an endoscope or other insertion device;

FIG. 17 shows a side view of a distal end of an alternate ligating banddispensing device specifically adapted for use with textured ligatingbands.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As illustrated in FIG. 1, a ligating band 1 is preferably formed as aring with an inner surface 2, an outer surface 4, a first side surface6, and a second side surface 8. Of course, those skilled in the art willunderstand that during manipulation, the ligating band 1 may beintentionally or accidentally twisted so that any of the surfaces 4, 6and 8 becomes the inner surface 2. Thus, in the ligating band 1according to the first embodiment of the invention includes texturing 10which covers all surfaces of the ligating band 1.

The ligating band 1 according to the first embodiment has across-section which is substantially rectangular. That is, the ligatingband 1 is formed as a portion of a cylinder. Those skilled in the artwill recognize that one or more of surfaces 2, 4, 6, or 8 may be roundedreducing the distinction between the various surfaces. However, thisdistinction between the various surfaces is unimportant so long as thesurface of the ligating band 1 which is in contact with the tissue to beligated includes texturing as described herein.

As shown in FIG. 1, the texturing 10 is comprised of a pattern of raisedbumps which are formed as cylindrical stems 12 and hemispherical caps14. Alternate forms of texturing 10 can employ one or more of a varietyof different shapes, including raised elongated members 16 as shown inFIG. 4, securing prongs 24 as shown in FIG. 9, or indentations (notshown) in the inner surface 2 of the ligating band 1. On any surface 2,4, 6 or 8 to which the texturing 10 is applied, the texturing 10 ispreferably evenly distributed.

The texturing 10 may preferably be applied to the ligating band 1 via amolding process, thereby making the texturing 10 an integral part of thestructure of the ligating band 1. Preferably, the texturing 10 and theligating band 1 are formed from latex or a synthetic equivalent thereof,such as polyisoprene. The ID (inner diameter) of the ligating bands 1may preferably be between 0.06 and 0.10 inches and is more preferablyapproximately 0.07 inches. The OD (outer diameter) of the ligating bandsis preferably between 0.20 and 0.24 inches, while the bands maypreferably be approximately 0.08 inches thick in a directionsubstantially parallel to a central axis of the ligating bands 1. Ofcourse, those skilled in the art will recognize that such a ligatingband may easily be twisted so that the ID surface becomes the ODsurface, etc. and that it may therefore be preferable to make thethickness of the band in each direction between 0.06 to 0.18 inches.

The texturing 10 is applied to the ligating band 1 so that the raisedbumps on a first side 18 of the inner surface 2 and the raised bumps ona second side 20 thereof combine to form an interlocking pattern. Byinterlocking those skilled in the art will understand that the raisedbumps on both the first side 18 and the second side 20 hold the tissueto be ligated by the ligating band 1 more securely in place when theligating band 1 applies inward pressure on said tissue with the bumpsfrom one side forcing the tissue into a gap between the bumps on theother side. Thus, as shown in FIG. 4, raised elongated members 16 on thefirst side 18 of the inner surface 2 may also form an interlockingpattern with respect to the second side 20 of the inner surface 2.

As shown in FIG. 8, an ligating band 1 according to the presentinvention may also include one or more manipulating apertures 22. Ifmanipulating apertures 22 are used in conjunction with an ligating band1, it is preferable to have at least three manipulating apertures 22but, may have four or more. The purpose of the manipulating apertures 22is to allow the physician placing the ligating band of the presentinvention to control the proper placement of the ligating band on thetissue to be ligated by inserting tines 42 of a ligating band spreader38 into the apertures 22 and, by spreading the tines 42 apart,increasing the interior diameter d of the ligating band 1 so that theposition of the ligating band 1 on the tissue to be ligated may beadjusted to allow an additional amount of tissue to be drawn up throughthe interior diameter d of the ligating band 1. Alternatively, thephysician may use such a manipulating instrument 38 with an ligatingband 1 including apertures 22 to originally place ligating bands ontissue to be ligated. That is, the physician may place an ligating band1 including apertures 22 on the manipulating device, spread the tines 42to increase the diameter d and manually draw tissue through the centralopening in the ligating band 1. The physician may then release theligating band 1 to ligate the tissue.

With reference to FIG. 1, although it is preferable to have texturing 10on all surfaces 2, 4, 6 and 8 of the ligating band 1, it is notnecessarily required so long as the user ensures that the surfaceincluding the texturing 10 remains, through the placement procedure,positioned so that it contacts the surface to be ligated. In use, thetissue to be ligated is drawn up within the interior diameter d of theligating band 1. Thus, only texturing 10 placed on the surfacepositioned at inner surface 2 is designed to come in contact with thetissue to be ligated. FIG. 2 depicts an ligating band 1 according to thepresent invention wherein texturing 10 is provided only on the innersurface 2 and the outer surface 4, while FIG. 3 depicts an ligating band1 according to the present invention wherein texturing 10 is providedonly on the inner surface 2.

However, it is preferred that texturing 10 be provided on each ofsurfaces 4, 6 and 8 in addition to inner surface 2 as the ligating band1 may “roll” after during the dispensing procedure or after beingdispensed onto the tissue to be ligated. Thus, a physician cannot becertain that the ligating band 1 will not ultimately be turned “insideout” on the tissue to be ligated such that outer surface 4, for example,comes in contact with the tissue to be ligated rather than the innersurface 2.

With references to FIGS. 4 and 5, the texturing 10 may be comprised ofraised elongated members 16 and placed in such a manner that the raisedelongated members 16 are aligned perpendicular to the longitudinalcenterline Cl of the ligating band 1. Alternately, the raised elongatedmembers 16 may be placed at an angle, preferably between 30° and 60°, tothe longitudinal centerline Cl of the ligating band 1, as shown in FIGS.6 and 7. Alternatively, the raised elongated members 16 may be placedperpendicular to the longitudinal centerline Cl of the ligating band 1,as shown in FIG. 8.

In FIG. 9, securing prongs 24 are used to provide texturing 10 to theinner surface 2 of the ligating band 1. The securing prongs 24 performthe same function as either the other types of texturing 10 previouslydescribed; that is, the securing prongs 24 increase the resistance ofthe ligating band 1 to any forces acting to dislodge it from the tissueto be ligated.

The securing prongs 24 may alternately be configured as injection prongs26, as shown in FIG. 10. After tissue to be ligated has been drawnwithin the interior diameter d of the ligating band 1, the ligating band1 is allowed to return to its undeformed state, applying inward pressureon the tissue. By employing injection prongs 26, not only does theligating band 1 depicted in FIG. 10 securely hold the tissue to beligated in place, but it also pierces the tissue with the injectionprongs 26, thereby injecting a fluid held in an interior reservoir 28into the tissue. The fluid is injected as the return of the ligatingband 1 to its undeformed state compresses the reservoir 28. Thoseskilled in the art will recognize that this fluid may be a sclerotherapyagent, a healing agent or any other desired medicinal fluid.Alternatively, the fluid may be coated on an area F at the tips 30 ofthe injection prongs 26, so that the fluid F would be injected into thetissue after the tissue to be ligated has been drawn within the interiordiameter d of the ligating band 1 and the ligating band 1 has beenallowed to return to its undeformed state.

Alternately, injection prongs 26 may be used to transmit RF energy intothe section of tissue directly beneath the tissue to be ligated. Toachieve this, the structure illustrated as the reservoir 28, is replacedby a similarly shaped and situated electrically conductive member which,after the ligating band 1 has been positioned on the tissue, may becoupled to a source of RF energy via apertures 22 to cauterize thesurrounding tissue. Those skilled in the art will understand that theelectrically conductive material may be in the form of a spring or otherexpandable shape to allow the structure to expand and contract when theligating band is stretched or released.

In use, as shown in FIGS. 11-16, in use a physician first loads theligating band 1 onto the distal end of a ligating band dispenser 32,such as the ligating dispenser described in U.S. Pat. No. 5,356,416, sothat the interior diameter d of the ligating band 1 is substantiallygreater that its natural, pre-deformed interior diameter d.

Next the physician positions a distal aperture 34 of the ligating banddispenser 32 adjacent to a first section of tissue T1. The first sectionT1 is then drawn into the distal aperture 34, preferably under suction.Alternatively, the first section of tissue T1 may be drawn within thedistal aperture 34 by mechanical means, such as a forceps, jaws, clamp,or the like (not shown). The physician then triggers the ligating banddispenser 32 to release one or more ligating bands 1 over the targetedtissue T1.

As seen in FIG. 12, when the ligating band 1 has been dispensed from theligating band dispenser 32, the interior diameter d of the ligating band1 suddenly decreases as the ligating band 1 seeks to return to itspredeformed state. As the interior diameter d decreases, the texturing10 on the inner surface 2 of the ligating band 1 engages a portion 36 ofthe first section of tissue 33 and exerts inward pressure on the tissue36. The pressure on the tissue 39 stops all circulation through thetargeted tissue T1, thereby causing the portion 36 to die. The body thensloughs off the dead tissue 36. Alternatively, the dead tissue 36 may beremoved by mechanical means and aspirated into an endoscope, theligating band dispenser 32, or a similar device.

While the texturing 10 on the inner surface 2 of the ligating band 1 isexerting inward pressure on the tissue 36, the texturing 10 restrictsthe movement of the ligating band 1 over the tissue 36. Thus, theligating band 1 of the present invention is less likely than prior artligating bands to be displaced from the targeted tissue 36 in responseto outward pressures caused by the “pinching” of the targeted tissue 33or by the movement of blood or other fluid through the targeted tissueT1. In addition, when the texturing 10 on the inner surface 2 of theligating band 1 is exerting inward pressure on the tissue 36, it ispreferable that the texturing 10 on the first side 18 of the innersurface 2 remotely engages the texturing 10 on the second side 20 of theinner surface 2 through the portion 36 of tissue to form an interlockingpattern. By forming such an interlocking pattern, the texturing 10 moreeffectively restricts the movement of the ligating band 1 relative tothe tissue 36.

As discussed previously, the optional manipulation apertures 22 providethe physician with the ability to place the ligating band 1 directlyover the targeted tissue 36 and then decrease the interior diameter duntil the texturing 10 on the inner surface 2 of the ligating band 1engages and exerts inward pressure against the tissue 36. To positionthe ligating band 1, the physician loads the ligating band 1 onto aligating band spreader 38 by inserting each of the tines 42 into one ofthe manipulation apertures 22. Next, the physician manipulates theligating band spreader 38 to increase the interior diameter d of theligating band 1, and positions the ligating band 1 adjacent to the firstsection of tissue T1. A portion of the tissue is then drawn through theligating band 1 (using a clamping device 40 for example), and thephysician manipulates the ligating band spreader 38 to decrease theinterior diameter d of the ligating band 1 until the texturing 10engages the tissue 36.

By manipulating the ligating band spreader 38, the physician may notonly position the ligating band 1 over the tissue 36, but may alsosubsequently wholly or partially disengage the ligating band 1 from thetissue 36 to allow the physician to reposition the ligating band 1relative to the tissue 36. The physician may use the ligating bandspreader 38 whether the ligating band 1 was initially placed over thetissue 33 using a ligating band spreader 38 or using a ligating banddispenser 32.

Finally, FIG. 17 shows the distal end 50 of an alternate ligating banddispensing device including a ligating band supporting structure 52which has a diameter which decreases from a maximum diameter at aproximal end 54 to a minimum diameter at a distal end 58. Thus, theligating band supporting structure 52 may be formed as a portion of acone. As shown in FIG. 17, the proximal end 54 is received within asleeve 60 which forms an abutting surface 62 adjacent to the outersurface of the proximal end 54 so that, when a plurality of ligatingbands 4 are received on the ligating band supporting structure 52, aproximal most ligating band 4 may not move proximally past the abuttingsurface 62. The ligating band supporting structure 52 is coupled withinthe distal end 50 so that the ligating band supporting structure 52 maybe moved proximally relative to the abutting surface 62, for example bybeing screwed into the sleeve 60 by rotation about the central axis C inthe direction of arrow A. Thus, as the ligating band supportingstructure 52 is moved into the sleeve 60, the proximal-most ligatingband 4 abuts the abutting surface 62 and pushes the more distal ligatingbands 4 toward the distal end 58 until they are dispensed therefromone-by-one. Eventually, when the distal end 58 is drawn proximally pastthe abutting surface 62, the proximal-most ligating band 4 is dispensedfrom the ligating band supporting structure 52. Thus, as the forceurging the ligating bands 4 off the ligating band supporting structure52 is applied around the entire circumference of the ligating bands 4,the increased frictional forces associated with the textured ligatingbands according to the present invention may more easily be overcome.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in the art from the detaileddescription, wherein the preferred embodiment and several alternateembodiments of the invention have been shown and described. Thedescription of the preferred embodiment is simply by way of illustrationof the best mode contemplated for carrying out the invention. As will berealized, the invention is capable of other and different embodiments,and its several details are capable of modification in various respects,all without departing from the invention. Accordingly, the drawings anddescriptions are to be regarded as illustrative in nature, and not asrestrictive of the invention which is to be limited only by the claimsappended hereto.

What is claimed is:
 1. An elastic band for ligating tissue within aliving body, comprising: a ring formed of elastomeric material, the ringincluding an inner surface defining a lumen, and the ring including asecond surface; and a plurality of projections disposed on the innersurface and the second surface, each of the projections including asubstantially cylindrical stem and a substantially hemispherical cap,wherein prior to deployment the cylindrical stem and hemispherical capof the projections on the second surface have longitudinal axessubstantially orthogonal to longitudinal axes of the projections on theinner surface.
 2. The elastic band according to claim 1, wherein theprojections of the inner surface are arranged in a predetermined patternso that each of the projections faces across a central opening of thering to a space between projections formed on a corresponding oppositeportion of the inner surface.
 3. A method of ligating tissue within aliving body, comprising: positioning an elastic band which has beenstretched to increase the size of a central opening extendingtherethrough adjacent to a portion of tissue to be ligated, the elasticband including a ring formed of elastomeric material, the ring includingan inner surface and a second surface, the elastic band furtherincluding a plurality of projections disposed on the inner surface andthe second surface, each of the projections including a substantiallycylindrical stem and a substantially hemispherical cap, wherein prior todeployment the cylindrical stems and hemispherical caps of theprojections on the second surface have longitudinal axes substantiallyorthogonal to longitudinal axes of the projections on the inner surface;drawing a portion of tissue to be ligated through the central opening ofthe elastic band; and releasing the elastic band so that the size of thecentral opening decreases to grip the tissue received therein.
 4. Themethod according to claim 3, wherein the projections are arranged in apredetermined pattern so that each of the projections faces across acentral opening of the ring to a space between projections formed on acorresponding opposite portion of the inner surface.
 5. An elastic bandfor ligating tissue within a living body, comprising: a ring formed ofelastomeric material, the ring including an inner tissue engagingsurface, which, when in an operative position within the body, surroundsand directly contacts the tissue, and the ring including a secondsurface; an interior reservoir formed within the ring, the interiorreservoir sized to retain fluid; and a plurality of projections eachdisposed on and integrally formed with the inner surface, at least aportion of each of the plurality of projections being formed of theelastomeric material and each the projections including an injectionprong.
 6. A method of ligating tissue with a living body, comprising:positioning an elastic band which has been stretched to increase thesize of a central opening extending therethrough adjacent to a portionof tissue to be ligated, the elastic band including a ring formed ofelastomeric material and the elastic band including an electricallyconductive member extending from the inner surface to a contact pointaccessible from a proximal side of the elastic band, the ring includingan inner tissue engaging surface which, when in an operative positionwithin the body, surrounds and directly contacts the tissue, and theelastic band further including a plurality of projections each disposedon and integrally formed with the inner surface and each of theprojections including an injection prong; drawing a portion of tissue tobe ligated through the central opening of the elastic band; releasingthe elastic band so that the size of the central opening decreases togrip the tissue received therein; and applying RF energy to the tissuethrough the electrically conductive member.